U.S. Defense Secretary Chuck Hagel says the United States will continue to seek an international coalition in response to Syria's alleged use of chemical weapons, despite opposition by British lawmakers to any military action.

Hagel spoke to reporters in Manila Friday, after Britain's lower house of Parliament rejected a motion for British participation in a military strike. The non-binding vote is a setback to British Prime Minister David Cameron, who told lawmakers a military strike would be a response to a war crime, not an attempt to topple the Syrian government.

French President Francois Hollande said the British vote will not affect his country's position on Syria. In an interview with Le Monde newspaper, he said he does not favor international action merely to overthrow the government, but a chemical assault must not go unpunished.

Russian President Vladimir Putin's chief foreign policy aide said the British decision shows that "people are beginning to understand" the dangers of a military strike.

Meanwhile, Members of the U.S. Congress briefed by senior Obama administration officials Thursday say there is no doubt the Syrian government carried out a deadly chemical weapons attack last week near Damascus.

President Barack Obama is still deciding how to respond to Syria. A military strike against the Assad government appears to be the most likely course of action.

Democratic Representative Eliot Engel said the U.S. officials cited intercepted communications between senior Syrian officials. Engel also said intelligence showed the Syrians moved materials around in advance of a chemical strike.

Earlier Thursday, White House spokesman Josh Earnest said that along with circumstantial evidence, the United States has classified intelligence that undoubtedly points to an attack by the Syrian government.

Syria denies carrying out a chemical attack and accuses the rebels of using such weapons on Syrian soldiers.

U.N. Secretary-General Ban Ki-moon is urging world powers to hold off any action until a U.N. chemical weapons team completes its work. The inspectors are expected to leave Syria on Saturday.

After two days of closed-door meetings, diplomats from the five permanent Security Council members have been unable to agree on a possible military strike. The Obama administration has said it may act on its own against Syria if the U.N. continues what it calls "diplomatic paralysis."